1. Field of the Invention
The present invention relates generally to an improved method and apparatus for determining and visually displaying the frequency of a vibratory element of a musical instrument. Throughout this specification, the term "vibratory element" is employed in a general sense to include all frequency producing means whether mechanical, electrical, or otherwise.
2. Description of the Prior Art
All musical instruments of the acoustical variety and especially multistringed instruments such as guitars, violins, and pianos, require periodic, even daily, tuning to insure that they consistently reproduce a proper pitch when played. In the past, in the case of the piano, this periodic tuning has been accomplished manually by a skilled craftsman employing a set of tuning forks to provide audible reference frequencies. Being of simpler construction than the piano, instruments such as the guitar and the violin are not generally tuned by such a special skilled craftsman, but rely upon the skill of the individual musician for their tuning. In any event, the use of tuning forks is inherently an inaccurate method, is slow and tedious, and in the case of multistringed instruments such as pianos, requires skill far beyond that routinely available in today's society.
Because of this situation, electronic devices have been developed to provide such periodic tuning. Known devices generally provide information in the form of a frequency difference between an input signal as generated by a vibratory element, such as a string of a guitar, and the correct or desired frequency to be generated by that element. In these instances, when the frequency difference becomes small or zero, the element is properly tuned. Examples of some of the known devices are disclosed in the U.S. Patents to Allen, U.S. Pat. No. 3,881,389, Iannone, U.S. Pat. No. 3,896,697, Rosado, U.S. Pat. No. 4,018,124, Arpino, U.S. Pat. No. 4,041,831, and Calvin, U.S. Pat. Nos. 4,078,469 and 4,122,751. As disclosed, these devices utilize visual indicators which are sometimes in the form of meters or lights which turn on or off depending on whether or not the vibratory element is in tune, digital displays of frequency deviations, and use in one instance, of a stroboscope to display frequency deviation as apparent movement of dark and light spots on a disk. The patent to Mackworth-Young, U.S. Pat. No. 3,631,756, discloses an indicator in the form commonly known as a "magic-eye" according to which fluorescing sectors are moved towards or away from one another depending on whether the vibratory element is approaching or retreating from a desired tuned frequency.
These patents are generally representative of the prior art and, although they were deemed to be advances in the state of the art at the time that they were conceived and reduced to practice, they exhibit a number of drawbacks which have been considered during the development of the present invention. For example, in many instances, the known devices utilize complicated electrical or electronic circuitry which necessarily results in a high initial cost and are subsequently expensive to maintain. However, a major drawback of those devices described in the patents recited above is the fact that the information displayed begins to degenerate at the instant the string is plucked with the result that such information is of questionable accuracy after the initial value is displayed. Thereafter, the musician is not able to rely on the information displayed, but is forced to guess the actual value albeit based to some extent on the information displayed. An additional drawback of the known devices is the fact that they do not generally inform the musician of the particular frequency of the vibratory element being examined; rather, they inform the musician of the difference between the frequency of the vibratory element, as actuated, and the desired frequency for that element. In most instances, a competent musician is aware of the general frequency range for a particular vibratory element, although he may not know the exact frequency for that element. In any event, most musicians would rather be informed of the particular frequency being generated by an activated element and make the appropriate adjustment to bring it into tune, than to know only the frequency deviation between the actual and desired frequency.